Metal sheathed insulating blanket



April 1962 D. P. RUTTER ETAL 3,031,358

METAL SHEATHED INSULATING BLANKET Original Filed Nov. 12. 1953 ,IIIIIIIIIIIIIIIA r or n United States Patent 3,031,358 METAL SHEATHED INSULATING BLANKET Donald P. Rutter, Bernardsville, and Anthony E. Cirnochowski, Somerville, N.J., assignors to Johns-Manville C(orpfration, New York, N.Y., a corporation of New or Original application Nov. 12, 1953, Ser. No. 391,472, now Patent No. 2,975,821, dated Mar. 21, 1961. Divided and this application Dec. 31, 1959, Ser. No. 863,260

9 Claims. (Cl. 15444) This invention relates to heat insulation of the type comprising a sheet metal enclosed flexible insulation blanket adapted for application to high temperature curved surfaces such as presented by engine cylinders, the tail cones of jet engines, and the like, and to a method and apparatus for making such insulation. The invention relates particularly to improvements in such a corrugated sheet metal sheathed flexible insulation blanket as disclosed in United States Patent No. 2,576,698, issued November 27, 1951, in the name of Gaillard R. Russum, and to an improved method and apparatus for making insulation of the type disclosed in said patent. This application is adivision of copending application Serial No. 391,472, filed November 12, 1953, issued as U.S. Patent No. 2,975,821 on March 21, 1961.

As illustrated in Patent No. 2,576,698, it has been the practice to form that segment of the sheet metal enclosure which is to receive the corrugations to impart flexibility thereto with the corrugations extending transversely of the segment and to the direction of intended curvature. It has also been considered desirable to extend the side Walls of the segment at a relatively sharp angle to the corrugated base portion of the segment, so that the thickness of the insulating portion of the blanket is substantially uniform throughout its width. The use of such an angular corner construction, or so-called box edge, in the segment to be corrugated poses problems in the corrugating operation, principally the difiiculty of avoiding wrinkling and rupturing the sheet metal at the corner in the formation of corrugations in the base and side wall of the segment adjacent the corner. The formation of the corrugations in the side wall, as well as the base, is desirable to compensate for the shortening of the base when the corrugations are formed therein and to contribute to the flexibility of the segment when applied to the curved surface to be insulated. In one type of construction now employed, the corrugations running transversely of the base of the segment are formed with their lands extending inwardly from the inside face of the base, and the corrugations in the side walls are formed with their lands lying in substantially the same plane as the respective corrugations in the base, but with the lands formed outwardly from the outside faces of the side walls, so that the corrugations are reversed adjacent the corners. The resulting structure has the disadvantage that the lands of the side wall corrugations protrude in the direction in which they are visible in the completed blanket, so as to present a somewhat undesirable appearance. In certain installations, the projecting lands of the side walls are also undesirable from a structural standpoint.

It is an object of the instant invention to provide a type of corrugation in the base and side wall of the segment to be corrugated, which will be suitable to any angle made by the corner formed by the line of junction of the side wall and the base, without the disadvantages of having the corrugation protrude outwardly from the side wall.

It is a further object of the invention to provide a type of corrugation in the sheet metal segment to be corrugated in which the side wall of the segment ex- 3,d3l,358 Patented Apr. 24, 1962 tends from the base to form an angular corner therewith,

ment is preserved, and in which the respective base and side wall corrugations are neatly joined at the corner of the segment without cracks or ruptures.

The invention will be more fully understood and further objects and advantages thereof will become apparent when reference is made to the following detailed description of a preferred embodiment of the invention and the accompanying drawing in which:

FIG. 1 is a perspective view of a typical improved corrugated sheet metal sheathed insulating blanket of the instant invention;

FIG. 2 is an enlarged fragmentary view of the sheathed blanket of FIG. 1, showing a transverse section taken between corrugations thereof;

FIG. 3 is an enlarged fragmentary perspective View of one side or edge of the corrugated sheet metal segment of FIGS. 1 and 2, illustrating details of the corrugation formation at the corner, and of a flattened portion of the corrugation in an outer edge flange portion of the side wall; and

FIG. 4 is a view in cross-section taken on the line 44 of FIG. 3.

Referring to FIGS. 1 through 4, a metal sheathed insulating blanket '1 of the type described comprises a flexible thermal insulating blanket or filler material 2 enclosed by a sheathing comprising a relatively thin flexible sheet metal section 4 having a main body or base portion 6 and side walls 8 extending angularly therefrom, both in the same general direction, at relatively clearly marked lines of junction 9 with the base to form angular inside and outside corners 10 and 11 therewith. Formed in the base and side walls and extending transversely thereof, and with respect to the lines of junction are spaced corrugations 12 and 13, respectively, with the respective corrugation grooves 14, 14 formed in the outer faces of the base and side walls and with the respective corrugation lands 15, 15 all extending inwardly from the inner faces of the base and side walls, the portion of the axis of each of the corrugations of each side wall adjacent its respective line of junction with the base lying in substantially the same plane through that line of junction as the portion of the axis of the corresponding cor rugation in the base adjacent the line of junction. In the preferred form illustrated, in which the side walls extend substantially at right angles to the base, the ends of the walls 16 and lands 15 of the corrugations 12 in the base terminate substantially flush with the adjacent portions of the outside face of the respective side walls, as at 17 and the base corrugation grooves 14 open therethrough. The ends of the side Wall corrugations toward the lines of junction 9 are joined respwtively to the adjacent ends of corresponding base corrugations, each by a portion 17 of the metal of the side wall extending into that end of the groove of the sidewall corrugation and shaped complementary to the proximate end of the land of the corresponding base corrugation, and nesting therewith. The portion 17 forms in effect a saddle straddling the base corrugation land, and joined thereto on a U-shaped fold line 17 adjacent the corner and closing the adjacent end of the side wall corrugation, fold line 17 lying substantially flush with the outer face of the side wall, as previously indicated.

As will be more clearly apparent in FIGS. 3 and 4, the lands 15 of the side wall corrugations are flattened as at lsagainst the inside surface of their respective side walls for a portion of their lengths inwardly from the outer edge of the side wall in order to form a relatively flat edge flange portion 20. The edge flanges 20 are turned up on a line of told 21, positioned according to the desired thickness of the blanket, so as to lie substantially parallel with the base. A cover sheet 22, shaped and dimensioned to overlie the edge flanges and to span the base, preferably with some overlap, is secured to the edge flanges in any suitable manner, such as by an overlapping fold 23 spot-crimped as at 24 or otherwise secured to the edge flanges, to provide an effective seal against moisture penetration. The cover sheet and the corrugated section may be secured together in similar sealed-engagement at the ends of the blanket in any suitable manner, as by tapering the side walls adjacent their ends and making an overlapped and spot-crimped folded connection thereat such as illustrated at 23 24 An insulating blanket having a metal sheath formed as described fulfills the objects stated, being applicable to curved surfaces to be insulated, either with the corrugated segment turned inwardly toward the curved surface or in the reversed position in which the cover sheet is turned inwardly and the corrugated segment extends outwardly from the surface to be insulated. The construction described permits desired flexure in either di rection, and does not have a tendency to develop wrinkles or wrinkle ruptures during application. As is well understood in the art, if the sheathed blanket is to be applied to a frusto-conical surface such as the tail cone of a jet engine, its shape viewed in plan prior to application to the curved surface will be generally similar to that illustrated in FIG. 6 of the aforementioned Russum Patent No. 2,576,698.

From the above description, it will be evident that we have obtained the objects of our invention. While we have described our invention in rather -full detail, it will be understood that these details need not be strictly adhered to but that various changes and modifications may suggest themselves to one skilled in the art, all falling within the scope of the invention as defined by the subjoined claims.

What we claim is:

1. In a sheet metal enclosure for a flexible thermal insulating blanket applicable to cover a curved surface, a sheet metal section having a base and opposite side Walls extending angularly therefrom in the same general direction at relatively clearly demarked lines of junction therewith to form angular inside and outside corners, the base and side walls having spaced corrugations therein, with the corrugation grooves in their outer faces and the corrugation lands on their inner faces, the corrugations in said base and side walls extending transversely thereof and with respect to said lines of junction, the portion of the axis of each of the corrugations of each side wall adjacent its respective line of junction with the base lying in substantially the same plane through said line of junction as the portion of the axis of a corresponding one of the corrugations in the base adjacent said line of junction, the ends of the corrugations in said base terminating substantially flush with the adjacent portions of the outside face of the respective side walls, and said base corrugation grooves opening therethrough.

2. The invention as defined in claim 1, the lands of the side wall corrugations being flattened against the inside surface of their respective side walls for a portion of their lengths inwardly from the outer edge of the side wall toward its line of junction with said base.

3. An enclosure for a flexible thermal insulating blanket applicable to cover a curved surface, comprising, a sheet metal section as defined in claim 2, the edge portions of said side Walls including said flattened corrugation lands being turned back to form edge flanges, a cover sheet shaped and dimensioned to overlie said edge flanges and to span said base and being secured to said edge flanges, and thermal insulating material housed between said base, side walls, and cover.

4. In a sheet metal enclosure for a flexible thermal insulating blanket applicable to cover a curved surface, a sheet metal section having a base and opposite side walls extending angularly therefrom in the same general direction at relatively clearly demarked lines of junction therewith to form angular inside and outside corners, the base and side walls having spaced corrugations therein, with the corrugation grooves in their outer faces and the corrugation lands on their inner faces, the corrugations in said base and side walls extending transversely thereof and With respect to said lines of junction, the portion of the axis of each of the corrugations of each side wall adjacent its respective line of junction with the base lying in substantially the same plane through said ine of junction as the portion of the axis of a corresponding one of the corrugations in the base adjacent said line of junction, the ends of the corrugations in the side walls toward said lines of junction being joined respectively to the corresponding ends of the corrugations in said base each by a portion of the metal of the side wall extending into the end of the groove of the side wall corrugation adjacent the proximate end of the land of the corresponding corrugation in the base and forming a saddle straddling said end.

5. The invention as defined in claim 4, in which the ends of the corrugations in the base lie substantially flush, respectively, with the adjacent portions of the outside faces of the side walls.

6. The invention as defined in claim 5, in which the lands of the side wall corrugations are flattened against the inside surface of their respective side walls for a portion of their lengths inwardly from the outer edge of the side wall toward its line of junction with said base.

7. An enclosure for a flexible thermal insulating blanket applicable to cover a curved surface, comprising, a Sheet metal section as defined in claim 6, the edge portions of said side walls, including said flattened corrugation lands, being turned back substantially parallel to said base to form edge flanges, a metallic cover sheet shaped and dimensioned to overlie said edge flanges and being secured thereto and spanning said base, and thermal insulating material housed between said base, side walls, and cover.

8. A strip of sheet metal for use in forming a flexible envelope for covering a flexible heat insulation blanket, said strip comprising two walls meeting on a line of junction so as to form an angular outside and inside corner thereat, one of said walls having a corrugation therein, with the corrugation groove in its outside face and the corrugation land on its inside face, the length of the corrugation extending transversely with respect to said line of junction and terminating thereat so that the end of the corrugation walls at said line of junction lie substantially flush with the adjacent portions of the outside face of the other wall and the end of the corrugation groove at said outside face of said other wall opens therethrough, said other Wall having a corrugation therein, with the corrugation groove in its outside face and the corrugation land on its inside face, the length of the last mentioned corrugation extending transversely with respect to said line of junction, the land of the last mentioned corrugation lying in substantially the same plane at said line of junction and transversely thereof as the land of the first mentioned corrugation, the end of the last mentioned corrugation groove adjacent said corner being closed by a fold of the sheet metal of the wall in which it is formed, said fold being connected to and complementing in shape the adjacent end of the walls and land of the first mentioned corrugation.

9. In a sheet metal enclosure for a flexible heat insulating blanket applicable to cover a curved surface, a sheet metal section having a base and a side wall extending angularly therefrom and having a relatively clearly demarked line of junction therewith to form an angular inside and outside corner, said base having spaced corrugations therein, with the corrugation grooves in its outside face and the corrugation lands on its inside face, the lengths of said corrugations extending generally transversely of said base, said corrugation grooves extending at one end to said line of junction, said side wall having corresponding similarly spaced corrugations therein, with their grooves in its outside face and their lands on its inside face, the lands of said last mentioned corrugations lying respectively in substantially the same planes, at said corner and transversely of said line of junction, as the lands of the corresponding corrugations in said base, the lands of the corrugations in the side walls terminating respectively at one end adjacent the inside 15 of said corner and adjacent the end of the land of the corresponding corrugation in the base, the grooves of the corrugations in said side wall terminating respectively at one end adjacent said corner in a portion of said side wall turned back into said one end of the groove and shaped to fit complementally the configuration of the land and side walls of the corresponding corrugation in said base.

References Cited in the file of this patent UNITED STATES PATENTS 2,238,022 Johnson Apr. 8, 1941 2,576,698 Russum Nov. 27, 1951 Biordi et a1. Mar. 9, 1954 

1. IN A SHEET METAL ENCLOSURE FOR A FLEXIBLE THERMAL INSULATING BLANKET APPLICABLE TO COAVER A CURVED SURFACE, A SHEET METAL SECTION HAVING A BASE AND OPPOSITE SIDE WALLS EXTENDING ANGULARLY THEREFORM IN THE SAME GENERAL DIRECTION AT RELATIVELY CLEARLY DEMARKED LINES OF JUNCTION THEREWITH TO FORM ANGULAR INSIDE AND OUTSIDE CORNERS, THE BASE AND SIDE WALLS HAVING SPACED CORRUGATIONS THEREIN, WHICH THE CORRUGATION GROOVES IN THEIR OUTER FACES AND THE CORRUGATION LANDS ON THEIR INNER OUTER FACES AND TIONS IN SAID BASE AND SIDE EXTENDING TRANSVERSELY THEREOF AND WITH RESPECT TO SAID LINES OF JUNCTION, THE PORTION OF THE AXIS OF EACH OF ATHE CORRUGATIONS OF EACH SIDE WALL ADJACENT ITS RESPECTIVE LINE OF JUNCTION, THE BASE LYING IN SUBSTANTIALLY THE SAME PLANE THROUGH SAID LINE OF JUNCTION AS THE PORTION OF THE AXIS OF A CORRESPONDING ONE OF THE CORRUGATIONS IN THE BASE ADJACENT SAID LINE OF JUNCTION, THE ENDS OF THE CORRUGATIONS IN SAID BASE TERMINATING SUBSTANTIALLY FLUSH WITH THE ADJACENT PORTIONS OF THE OUTSIDE FACE OF THE RESPECTIVE SIDE WALLS AND SAID BASE CORRUGATION GROVES OPENING THERETHROUGH 